Photon Spectrum

Spectrum is an open-source-first messaging API platform built by Photon that gives developers and businesses programmatic access to iMessage, SMS/RCS, and other messaging channels. The core system is fully open-sourced and can be self-hosted using first-party and community platform adaptors, or used via Photon's managed cloud service. Spectrum supports iOS 26 features such as polls and background customization, and offers both direct and group messaging APIs. It is designed to scale from individual developers to large enterprises with dedicated infrastructure.

• iMessage API Access — Full direct and group messaging API access with unlimited daily messages and RCS/SMS fallback included on all plans.
• iOS 26 Feature Support — Leverage the latest iOS 26 messaging features including polls and background customization through the API.
• Cold Outreach — Business and Enterprise plans support cold outreach to up to 50 new contacts per day per line.
• Self-Hosting Option — The core Spectrum system is fully open-sourced; self-host using first-party or community adaptors without requiring the cloud service.
• Multi-Channel Roadmap — WhatsApp, Telegram, and Phone Call channels are coming soon, with SMS/RCS already included across all plans.
• Dedicated Infrastructure — Business and Enterprise tiers offer dedicated iMessage lines, dedicated Slack & Discord support channels, and enterprise-grade SLAs.
• Custom iMessage Mini Apps — Business and Enterprise plans allow you to bring your own iMessage mini apps for richer messaging experiences.
• Scalable User Limits — Plans range from up to 10 users on Free to unlimited users on Business (with Auto Top-Up) and Enterprise.